Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium.
Department of Medical microbiology, AZ Sint-Jan, Brugge, Belgium.
Acta Gastroenterol Belg. 2022 Jul-Sep;85(3):522-524. doi: 10.51821/85.3.9108. Epub 2022 Jun 30.
Hemophagocytic lymphohistiocytosis (HLH) is a life threatening condition caused by inappropriate immune activity. Infection is often the trigger, both in genetically predisposed and in sporadic cases. Although more commonly seen in the paediatric population, patients of all ages can be affected.
A 26-year-old male patient with Crohn's disease, treated with ustekinumab, presented with high fever, epistaxis and anorexia. Laboratory results showed pancytopenia, and a high serum levels of ferritin and LDH. Colonoscopy revealed only mild signs of disease activity. CT-scan showed splenomegaly and multiple lymphadenopathies. Bone marrow aspirate was suggestive for hemophagocytosis. PCR & serology for parvovirus B19 came back positive. Treatment with ustekinumab was temporarily put on hold and supportive care was given. Viral replication decreased and he recovered completely.
There is a known association between HLH and Crohn's disease. This is probably because they are more susceptible to infections with CMV, EBV and parvovirus B19, all known as triggers for HLH. The role of ustekinumab is unclear: did it play a role in the pathophysiological evolution of this primo-infection with parvovirus B19? On the other hand, did it contribute to the rather mild course of the disease, acting as a immunomodulator that works on interleukin-12, a cytokine that plays a role in HLH? Further study is warranted to answer these questions.
噬血细胞性淋巴组织细胞增生症（HLH）是一种由免疫功能失调引起的危及生命的疾病。感染通常是其诱因，无论是在遗传易感性病例还是散发性病例中都是如此。尽管这种疾病在儿科人群中更为常见，但所有年龄段的患者都可能受到影响。
一名 26 岁男性克罗恩病患者，接受乌司奴单抗治疗，出现高热、鼻出血和食欲不振。实验室结果显示全血细胞减少，血清铁蛋白和乳酸脱氢酶水平升高。结肠镜检查仅显示轻度疾病活动迹象。CT 扫描显示脾肿大和多个淋巴结病。骨髓抽吸物提示噬血细胞现象。细小病毒 B19 的 PCR 和血清学检查结果为阳性。乌司奴单抗治疗暂时停止，给予支持性护理。病毒复制减少，患者完全康复。
HLH 与克罗恩病之间存在已知关联。这可能是因为它们更容易感染巨细胞病毒、EB 病毒和细小病毒 B19，这些病毒都已知是 HLH 的触发因素。乌司奴单抗的作用尚不清楚：它是否在细小病毒 B19 原发性感染的病理生理演变中发挥了作用？另一方面，它是否通过作为一种免疫调节剂来发挥作用，从而对白细胞介素-12 产生影响，白细胞介素-12 在 HLH 中发挥作用，从而对疾病的相对较轻的病程起到作用？需要进一步研究来回答这些问题。
